Toyota RAV4 (XA40) 2013-2018 Service Manual: Internal control module random access memory (ram) error
Description
The ecm continuously monitors its own internal memory status, internal circuits, and output signals transmitted to the throttle actuator. This self-check ensures that the ecm is functioning properly. If any malfunction is detected, the ecm sets the appropriate dtc and illuminates the mil.
The ecm memory status is diagnosed by internal mirroring of the main cpu and the sub cpu to detect random access memory (ram) errors. The two cpus also perform continuous mutual monitoring. The ecm illuminates the mil and sets a dtc if: 1) outputs from the two cpus are different or deviate from the standards, 2) the signals sent to the throttle actuator deviate from the standards, 3) a malfunction is found in the throttle actuator supply voltage, and 4) any other ecm malfunction is found.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Inspection procedure
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
- Check any other dtcs output (in addition to dtc p0604, p0606, p0607 or p0657)
- Connect the intelligent tester to the dlc3.
- Turn the ignition switch on.
- Turn the tester on.
- Select the following menu items: diagnosis / enhanced obd ii / dtc info / current codes.
- Read dtcs.
System voltage
Description
The battery supplies electricity to the ecm even when the ignition switch is
in the off position. This
power allows the ecm to store data such as dtc history, freeze frame data and ...
Starter relay circuit high
Description
While the engine is being cranked, the positive battery voltage is applied to
terminal sta of the ecm. If
the ecm detects the starter control (sta) signal while the vehicle is bein ...
Other materials:
Knock sensor 1 circuit
Description
Flat type knock sensors (non-resonant type) have structures that can detect
vibrations over a wide band
of frequencies: between approximately 6 khz and 15 khz.
A knock sensor is fitted onto the engine block to detect engine knocking.
The knock sensor contains a piezoelectri ...
Only driver door lock / unlock functions do not operate
Description
The main body ecu receives lock / unlock switch signals and activates the
door lock motor accordingly.
Wiring diagram
Inspection procedure
Perform active test by intelligent tester (door lock)
Select the active test, use the intelligent tester to
generate a control c ...
Master cylinder pressure sensor malfunction
Description
The master cylinder pressure sensor is connected to the skid control ecu in
the abs and traction
actuator.
Dtc c1281/81 can be detected when the master cylinder pressure sensor sends a
master cylinder
pressure signal or test mode ends. Dtc c1281/81 is output only in test mo ...
